_187ọ.] Geology and Paleontology. 719 
It is impossible to give any conception of the vast amount of 
research in this valuable essay in a short review, and, therefore, 
our readers are referred to the paper itself. 
In the same number of the Revue will be found a report upon 
the Ethnographic chart of France, by Dr. Gustav Lagneau, and a 
criticism of several works upon circumcision as practiced in 
various parts of the world, by M. Zaborowski. 
GEOLOGY AND PALAONTOLOGY. 
GrotocicaL Notes.—At the Saratoga meeting of the American 
Association for the Advancement of Science Prof. J. P. 
State Geologist of Pennsylvania, read a very long paper on the 
progress of the Second Geological Survey of Pennsylvania. The 
very valuable results accomplished by this survey, both for scien- 
tific and economic purposes, were fully set forth, and the impor- 
tance of completing it was dwelt upon. 
Prof. R. P. Whitfield gave notice of the occurrence of rocks in 
Central Ohio, representing the Marcellus shales of New York. 
A brief dissertation on the geology of Port Henry, New York, 
worked are imported yearly, principally from Brazil, and sold at 
public auction, the owners of the wheels buying each the amount 
he can work up during the year. Many of these mills date back 
to the middle ages. After the secret of coloring was discovered 
from the Romans, it was found that the Brazilian agates were 
